Undigested and dewatered sludge at 10% total solids was pretreated at 60 °C for 3 h and fed to a lab-scale horizontal anaerobic bioreactor for 130 days with solids retention time (SRTs) from 25 to 16 d. The low-thermal pretreatment enabled higher net energy production, improved sludge treatment efficiency, and enhanced digestion stability. The highest average biomethane yield and production rate were 138.5 mL/g VS and 0.43 L/L.d, respectively, and the economic benefit was expected to be the maximum at SRT 16 d. Pretreatment did not increase the specific methanogenic activity per unit methanogen, but resulted in higher abundance of methanogenic archaea and hydrolytic bacteria. Methanogenic population shifted from hydrogenotrophic to acetoclastic, consistent with predicted gene expression at SRT equal or below 20 d. Anaerobic digestion along with low-thermal could be a feasible management strategy for undigested dewatered sludge from small WWTPs.
|Publication status||Published - 2021 Dec|
Bibliographical noteFunding Information:
This work was supported by the Korea Environment Industry & Technology Institute (KEITI), through Project for developing innovative drinking water and wastewater technologies, funded by the Korea Ministry of Environment (MOE) (ARQ202001174001). This work was also supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (20194110100010).
© 2021 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Renewable Energy, Sustainability and the Environment
- Waste Management and Disposal